聚乙烯纤维加强聚甲基丙烯酸甲酯的机械性能测试

目的　观察聚乙烯纤维对聚甲基丙烯酸甲酯是否有加强作用。方法　采用自制模具,制作化学固化聚甲基丙烯酸甲酯(PMMA)组、化学固化PMMA加0·25 mm结扎丝组、化学固化PMMA加Ribbond聚乙烯纤维组3组试样,共28个。用万能材料实验机进行三点弯曲实验,记录试样的弯曲强度和弹性模量值,并进行统计分析。结果　化学固化PMMA组的弯曲强度为(51·383±2·761)MPa,弹性模量为(179 1·2±113·760)MPa。化学固化PMMA加 0·25 mm结扎丝组的弯曲强度为(58·725±1·218)MPa,弹性模量为(209 2·76±120·280)MPa。Ribbond聚乙烯纤维加强组的弯曲强度为(80·975±2·580)MPa,弹性模量为(286 6·53±107·510)MPa。经单因素方差分析各组之间皆有显著性差异(P<0·001)。Newman-Keuls法检测各组之间均有显著性差异(P<0·05)。结论　Ribbond聚乙烯纤维加强能显著提高聚甲基丙烯酸甲酯的弯曲强度和弹性模量。     

前牙玻璃纤维强化复合树脂粘结桥的强度

目的　对前牙玻璃纤维强化复合树脂粘结桥的力学性能进行初步的探讨。方法　通过预制铜制标准模型 ,保证固位翼三维恒定的情况下 ,以Sinfony复合树脂制作不加纤维和加纤维的上中切牙粘结桥共 2 6例 ,在37± 1℃的蒸馏水中保存 10天后 ,在万能力学试验机上分别从切端顺牙长轴方向和舌侧垂直于牙长轴方向以1mm/min的速度加压 ,得出折裂力值。结果　由切端顺牙长轴方向垂直加力时 ,经纤维强化的粘结桥的折裂力值较未经强化的粘结桥的折裂力值出现了显著的提高 ,达到 4 97.4± 90 .3N ;舌侧垂直加力时 ,两组的折裂力值无显著性差别。结论　前牙玻璃纤维强化复合树脂粘结桥承受轴向力的能力显著增强 ,其强度能满足切牙区正常牙合力及咀嚼功能的要求     

玻璃纤维增强复合树脂结合界面的研究

目的：研究玻璃纤维增强复合树脂中纤维与树脂界面结合的情况。方法：将玻璃纤维分别按预处理和预浸润的不同分为六组，测试各组的挠曲强度，冲击强度，在扫描电镜和X射线电子能谱仪下，分析界面结合的好坏，结果：经过KH－550预处理的粉液比为1：1的混合物预浸润后，纤维与树脂结合最好。结论：采用合适的预处理和预浸润，有利于增加玻璃纤维增强复合树脂的机械性能。     

云纹干涉法比较不同纤维加强聚合瓷的弹性模量研究

目的 运用云纹干涉法比较3种纤维对聚合瓷弹性模量的加强作用.方法 选用高强玻璃纤维S-Glass、芳纶纤维Kevlar-49及超高聚乙烯纤维UHMWPE 3种不同的纤维加入Solidex聚合瓷中,以不加纤维的Solidex聚合瓷作为空白对照,制作4组试件,每组3个.在试件表面转移光栅,采用三点弯曲加载方法,加载后采集u场及v场云纹干涉条纹,测定其弹性模量,并进行统计分析.结果 空白对照组、S-Glass组、Kevlar-49组和UHMWPE组平均弹性模量分别为(5.72±0.16) Gpa、(11.48±0.12) Gpa、(6.24±0.38) Gpa和(8.36±0.09) Gpa,3种纤维的加强效果为S-Glass＞Kevlar-49＞UHMWPE,各组间均有显著差异(P＜0.005).结论 S-Glass纤维对聚合瓷的弹性模量加强效果最明显,UHMWPE纤维加强效果最弱;云纹干涉法可用于不同纤维加强聚合瓷弹性模量的比较研究.     

晶须-颗粒复合体对光固化复合树脂力学性能的影响

目的 研究硼酸铝晶须-二氧化硅颗粒(ABw-SiO2)复合体对光固化牙科复合树脂弯曲性能的影响.方法 以ABw和SiO2比例、正硅酸乙酯(TEOS)用量、硅烷偶联剂用量和填料复合体用量作为实验因素,设计L9(3)4正交试验,制作试件并测试其弯曲强度和弯曲弹性模量;利用扫描电镜观察熔附体形貌.并对弯曲性能最优组与最差组试件行断面扫描.以未加填料的基质组作为阴性对照,Z100(A2色)为阳性对照.结果 最优组弯曲强度达(123.14±17.37)MPa,与基质组差异有统计学意义.与Z100(A2)复合树脂间差异无统计学意义;弯曲弹性模量为(8.75±0.459)GPa.结论 正交试验因素对光固化牙科树脂的弯曲性能有显著影响;ABw-SiO2填料复合体可以显著提高光固化牙科树脂的弯曲性能.     

固化工艺对晶须熔附颗粒复合树脂性能的影响

目的研究固化工艺对硼酸铝晶须熔附SiO_2颗粒(ABw-SiO_2)复合树脂性能的影响。方法根据胺活化剂(DHET)在复合树脂中的质量百分数,分为0.2%,0.3%和0.4%3个实验组,光固化型作为对照组,分别制作ABw-SiO_2复合体牙科复合树脂试件,检测试件弯曲强度和弯曲弹性模量;傅立叶变换红外光谱仪(FTIR)测试树脂的双键转化率。结果3组双固化ABw-SiO_2颗粒复合树脂弯曲性能差异无显著性。双固化型ABw-SiO_2颗粒复合树脂双键转化率为(62.23±1.43)%,光固化型为(55.96±1.86)%。结论双固化型ABw-SiO_2复合树脂的双键转化率高于光固化型树脂。     

Pontic制作纤维桩的弯曲强度和弯曲模量的研究

目的:检测Pontic制作纤维桩的弯曲强度和弯曲模量,为:Pontic制作纤维桩的临床应用提供理论基础.方法:在Instron-8841万能实验机上用三点弯曲的方法,在Pontic制作的纤维桩的中央加载,直至试样断裂,记录最大载荷值.同时用玻璃纤维预成根管桩、氧化锆预成根管桩、Ni-Cr合金铸造根管桩、不锈钢预成根管桩和钛合金预成根管桩进行对比实验.结果:Pontic制作的纤维桩的弯曲强度为(600±10)MPa,弯曲模量为(18±1.2)Gpa;Pontic制作纤维桩的弯曲强度与玻璃纤维预成桩的弯曲强度无统计学差异(P＞0.05).结论:Pontic制作的纤维桩弯曲强度能够达到临床应用要求.     

玻璃纤维强化复合树脂前牙粘结桥临床应用初探

目的 :探讨前牙玻璃纤维强化复合树脂粘结桥 (GFRC RBFPD)修复方法和评价短期临床效果。方法 :收集修复门诊 3 0名前牙缺失病例 ,缺失 1颗牙者 2 7例 ,缺失 2颗牙者 3例。其中基牙不需牙体预备的 16例 ,少量牙体预备的 14例。采用STICK预浸透玻璃纤维强化的Sinfony复合树脂制作粘结桥。应用All Bond 2树脂粘结材料粘结修复体。临床进行定期检查 ,全面评价使用效果。结果 :2 6例 6个月后临床复查 ,2 3例 (88.5 % )GFRC RBFPD不松动 ,修复体完好 ,无折断、缺损或过度磨耗 ,无明显着色 ,固位体边缘与粘结剂界面临床观察结合良好。 2例 (7.7% )在使用中出现脱粘 ,1例 (3 .8% )折断。 2 4例 18个月后临床复查 ,其中 3例 (12 .5 % )脱粘 ,3例 (12 .5 % )折断 ;基牙的探诊出血与对照牙比较均有显著性差别 (P <0 .0 5 )。结论 :GFRC RBFPD是一种微介入、无金属的固定修复方法 ,向患者提供了传统固定桥以外另一种固定修复方式。其支架强度和粘结强度需进一步提高 ,临床应用效果应长期观察。     

纳米二氧化硅含量对硼酸铝晶须-二氧化硅熔附体填料复合树脂弯曲性能的影响

目的研究正硅酸乙酯（TEOS）水解所得纳米二氧化硅（SiO2）含量对硼酸铝晶须（AlBw）与SiO2熔附体填料复合树脂弯曲性能的影响。方法采用TEOS溶胶－凝胶法制得纳米SiO2,按不同比例通过高温烧结使其熔附于AlBw表面,制作试样并测试其弯曲强度和弯曲弹性模量;利用透射电镜（TEM）观察高温处理过程对晶须表面形态的影响以及不同比例的熔附体形貌。结果AlBw-SiO2熔附体复合填料可显著提高牙科复合树脂的弯曲性能;AlBw和SiO2的质量比为3∶1时牙科复合树脂的弯曲强度达（130.29±8.38）MPa。结论TEOS溶胶－凝胶法水解所得的纳米SiO2含量可改善AlBw-SiO2熔附体填料复合树脂的弯曲性能。     

FRC 桩钉与三种非金属核材料粘结性能的对照研究

我们研制出弹性模量与牙体组织接近且美观性好的高强玻璃纤维增强EAM树脂复合材料 (fiberreinforcedcomposite ,FRC)桩钉 ,弯曲强度大于 12 0 0MPa ,经临床初步应用效果理想。本项实验旨在比较三种非金属桩核成形材料与预成FRC桩钉的粘结力 ,指导临床选择适合FRC桩钉用的核材料。1.材料和方法 :①材料 :自制FRC桩钉 (直径 1 78mm、长 4cm ) ;CoreshadeGlasIonomerCement (ShoFu ,Japan) ;AB组分双糊剂型复合树脂 (第四军医大学口腔医学院研制 ) ;Charisma通用型复合树脂及釉质粘合剂 (Kulzer,Germany) ;Dentcolor固化箱 (Kulze…     

The flexural properties of fiber-reinforced composite with light-polymerized polymer matrix

PURPOSE: The aim of this study was to measure the flexural strength and the elastic modulus of composite resin with and without reinforcing fibers and to evaluate the reinforcing effect of various fibers. MATERIALS AND METHODS: A polyethylene fiber (Ribbond), a polyaramid fiber (Fibreflex), and three glass fibers (FibreKor, GlasSpan, Vectris) were used to reinforce composite resins. The flexural strength and elastic modulus of specimens in the three-point bending mode were measured using a universal testing machine at a cross-head speed of 1 mm/min after storage in water at 37 degrees C for 24 hours. All tests were carried out in a water bath at 37 degrees C. The data were analyzed using analysis of variance and the Sheffé test at P= 0.05. After testing, the fractured surface was evaluated using a scanning electron microscope at 50x, 500x, and 3,000x magnifications. RESULTS: Yield flexural strengths of nonreinforced resins were 48 to 56 MPa, and those of reinforced resins were 56 to 134 MPa. Ultimate flexural strengths of nonreinforced specimens were 96 to 119 MPa, and those of reinforced ones were 203 to 386 MPa. Elastic modulus of nonreinforced resin was 6 to 9 GPa, and fiber reinforcing increased the value to 9 to 15 GPa, while it had no effect in Ribbond. CONCLUSION: Most of the fibers used in this study increased both yield and ultimate flexural strengths of composite resins, with the exception of the yield strength of Vectris. GlasSpan, Fibreflex, and FibreKor were effective in reinforcing elastic modulus, while Ribbond had no effect on it. Unidirectional glass fibers and polyaramid fiber were effective in reinforcing both flexural strength and elastic modulus of composite resin.     

GI-Ⅱ型着色玻璃渗透后渗透陶瓷的性能测试

目的 :探讨用GIⅡ型着色渗透玻璃渗透后的渗透陶瓷底层材料的热膨胀性能、机械力学性能和密度 ,为材料性能的改进和临床应用奠定基础。方法 :选用GIⅡ型着色渗透玻璃的IG2色玻璃料及GIⅡ型氧化铝粉体 ,制作氧化铝基体及渗透陶瓷样本 ,在TMA2940型热分析仪上绘制样本的热膨胀曲线 ,计算热膨胀系数 ;三点弯曲法测定渗透陶瓷材料的挠曲强度和弹性模量 ,显微压痕法测量断裂韧性和维氏硬度 ;重量体积法测定其密度。结果 :渗透陶瓷的热膨胀系数为 7.620×10(6)℃(-1)（2 5～ 5 0 0℃ ） ,略高于Vitaduralpha饰面瓷的热膨胀系数。材料的三点挠曲强度、弹性模量、维氏硬度、显微断裂韧性和密度分别为 389.6MPa、92GPa、9.409GPa、3.2425MNm3/2和3.662g/cm3 。结论 :用GIⅡ型着色渗透玻璃渗透后的渗透陶瓷底层材料 ,其热膨胀性能与Vitaduralpha饰面瓷匹配 ,机械强度也达到了临床应用的要求。     

The effect of fiber position and polymerization condition on the flexural properties of fiber-reinforced composite

The aim of this study was to investigate the influence of the position of the fiber rich layer on the flexural properties of fiber-reinforced composite (FRC) construction. In addition, the total residual monomer content of FRC was quantitatively determined to find out the difference of the effectiveness of two types of light-curing units using liquid chromatography (HPLC). Unidirectional continuous E-glass FRC and hybrid particulate filler composite resins were used in the fabrication of test specimens. Four different positions of the FRC layer were used: compression, neutral, tension, and vertical side position. A three-point bending test (ISO 10477) was performed to measure the flexural properties of the specimens. Position of the FRC layer had a significant effect on the flexural strength (p<0.001, ANOVA). Also, the type of light-curing device had an effect on flexural strength (p<0.001). Specimens with FRC positioned on the compression side showed flexural strength of approximately 250 MPa, whereas FRC positioned on the tension side showed strength ranging from 500 to 600 MPa. Mean flexural modulus with FRC placed horizontally ranged between 9-12 GPa; no significant difference was found between these groups. However when fiber reinforcement was positioned vertically, the flexural modulus raised up to 16 GPa. Specimens with 24 vol% glass fibers contained 52% less residual monomer than specimens without glass fibers. The monomer content was lower in specimens polymerized with the curing device with higher polymerization temperature. In order to optimize flexural strength of low fiber volume fraction, the fibers should be placed at the tension side of the specimen.     

Model System for Measuring the Effects of Position and Curvature of Fiber Reinforcement Within a Dental Composite

Purpose: The aim of this study was to compare the effect of fiber curvature and position on flexural strength (FS), toughness, and elastic modulus in a dental flowable composite test specimen. Methods and Materials: Test specimens made of composite resin (Denfil Flow) were reinforced with preimpregnated glass fibers (Interlig). Control specimens (group A) did not contain fiber reinforcement. Fibers were placed with different positions and orientations into the test specimens (2 mm × 2 mm × 25 mm) (groups B, C, D). The test specimens (n = 10) were stored in distilled water for 3 days at 37°C before testing in a three‐point loading test (ISO 10477) at a crosshead speed of 1 mm/min to determine FS, flexural modulus (FM), and toughness. Data were analyzed with 1‐way analysis of variance and Tukey HSD (σ= 0.05). Results: The FM varied from 4.7 ± 0.5 to 6.7 ± 0.5 GPa. The lowest flexural strength and toughness values in reinforced specimens resulted from compression side fiber reinforcement (132 ± 12 MPa, 21 ± 4 MJ) and the highest from curved fiber reinforcement (174 ± 8 MPa, 83 ± 28 MJ), though this was not statistically significant from tension‐side reinforcement. Although the toughness of the curved reinforced group was significantly higher than other groups, the flexural strength of curved reinforcement was not significantly higher than tension‐side reinforcement. Conclusion: Position and fiber orientation influenced the flexural strength, FM, and toughness. The most effective in increasing toughness was curved placement of fibers.     

Mechanical properties and wear behavior of light-cured packable composite resins.

OBJECTIVES: Determination of flexural strength, flexural modulus, fracture toughness and wear resistance of three packable composites (Solitaire, Surefil, ALERT) and a packable ormocer (Definite) in comparison with an advanced hybrid composite (Tetric Ceram) and an ion-releasing composite (Ariston pHc). METHODS: Flexural strength, flexural modulus and fracture toughness of each material were determined in three-point bending (each test n = 10). Single-edge notched-bend specimens were used to evaluate the fracture toughness (K1C). Wear of the materials (n = 8) was determined in a pin-on-block-design with a spherical Degusit antagonist at 50 N vertical load and quantified by a replica technique using a 3D-laser scanner. Replicas were made after 6000, 10,000, 30,000 and 50,000 load cycles. The mean wear rate (MWR (micron 3 cycle-1)) was obtained by a linear regression analysis in the steady-state of the time-wear-curve. All results were statistically analyzed with ANOVA and post hoc Tukey HSD tests (p < 0.05). RESULTS: ALERT exhibited the highest flexural modulus (12.5 +/- 2.1 GPa) and K1C (2.3 +/- 0.2 MN m-3/2), but the lowest wear resistance (8275 micron 3 cycle-1). Solitaire presented the highest wear resistance (1591 micron 3 cycle-1), but significantly lower flexural strength (81.6 +/- 10.0 MPa), flexural modulus (4.4 +/- 0.3 GPa), and K1C (1.4 +/- 0.2 MN m-3/2) than all other materials. Surefil revealed a significantly higher flexural modulus (9.3 +/- 0.9 GPa) and wear resistance (3028 micron 3 cycle-1) than Tetric Ceram (6.8 +/- 0.5 GPa; 5417 micron 3 cycle-1) and Ariston pHc (7.3 +/- 0.8 GPa; 7194 micron 3 cycle-1). SIGNIFICANCE: The tested packable composite resins differed significantly in their mechanical properties. This study suggested that fracture and wear behavior of the composite resins are highly influenced by the filler system. Overall, Surefil demonstrated good fracture mechanics parameters and a low wear rate.     

Comparison of flexural properties of composite restoratives using the ISO and mini-flexural tests

The purpose of this study was to investigate the flexural properties (flexural strength and flexural modulus) of four commercial composite restoratives (Silux Plus, Z100, Ariston and Surefil) using the ISO 4049 flexural test (IFT) and a mini-flexural test (MFT). Both tests involved the use of three-point loading and the same fixture. The difference between the tests was in the length of the composites specimens and the distance between the supports [20 mm (IFT) and 10 mm (MFT)]. Six specimens were made for each material and flexural test. Test specimens [25 x 2 x 2 mm (IFT) and 12 x 2 x 2 mm (MFT)] were fabricated according to manufacturers' recommendations. After light-polymerization, the specimens were stored in distilled water at 37 degrees C for 24 h. The specimens were subsequently blotted dry, measured and subjected to flexural testing using an Instron Universal Testing Machine with a crosshead speed of 0.75 mm min(-1). Data was analysed using anova/Scheffe's, paired samples test (P < 0.05) and Pearson's correlation (P < 0.01). For both IFT and MFT, results of statistical analysis of flexural strength were identical. Silux had significantly lower flexural strength compared with the other composites and the flexural strength of Ariston was significantly lower than Z100 and Surefil. For IFT, the flexural modulus of Z100 was significantly higher than Silux, Ariston and Surefil while for MFT, Silux had significantly lower modulus compared with Z100, Ariston and Surefil. A significant, strong and positive correlation (r = 0.95) was observed for flexural strength between IFT and MFT. Correlation for flexural modulus was also significant and positive but was weaker (r = 0.53). As MFT has the advantage of ease of specimen fabrication and is more clinically realistic, it is suggested for the testing of composite restoratives. CLINICAL RELEVANCE: The mini-flexural test may be better than the ISO flexural test for screening of composite restoratives for clinical applications.     

GI-Ⅱ型着色渗透玻璃的研制

目的:探讨GI- Ⅱ型着色渗透玻璃的制作工艺,并对着色渗透玻璃的相关性能进行测定。方法:优选法确定玻璃配方,测定热膨胀曲线,计算热膨胀系数、玻璃转化和软化温度;用三点弯曲法测挠曲强度和弹性模量,显微压痕法测断裂韧性和维氏硬度;用棱镜折光仪测定玻璃的折射率;用差热分析和X 衍射的方法测定玻璃渗透烧烤前后的稳定性。结果:GI- Ⅱ型着色渗透玻璃的热膨胀系数为61997 ×10-6 ℃-1 (25～500 ℃) ,玻璃转化和软化温度分别为635 ℃和650 ℃,主折射率为1164 ,三点弯曲强度为96127 MPa ,弹性模量为31116 GPa ,维氏硬度为51534 GPa ,显微断裂韧性为1105 MPa·m1P2 ,密度为31214 gPcm3 。GI- Ⅱ型着色渗透玻璃在特定条件下有乳浊产生,但在渗透烧烤程序下具有良好的稳定性。结论:GI- Ⅱ型着色渗透玻璃具有良好的机械物理性能和热稳定性。     

Influence of the mechanical properties of composites for indirect dental restorations on pattern failure

This study evaluated the fracture pattern of four composites for indirect dental restoration relating to three-point flexural strength, compressive strength and modulus of elasticity (Solidex, Artglass, belleGlass, and Targis). Ten specimens of each composite were tested in a universal testing machine at 0.5 mm/min crosshead speed for flexural strength and 1mm/min for compressive strength. Fracture pattern was classified as complete or partial fracture. Modulus of elasticity was calculated from flexural strength data. Composites polymerized under high temperatures (belleGlass and Targis) had higher flexural strength and elastic modulus values than composites polymerized by light (Artglass and Solidex). However, they failed earlier under compression because they were more rigid and showed partial fracture in the material bulk.     

Flexural properties and impact strength of denture base polymer reinforced with woven glass fibers.

OBJECTIVES: The present investigation was undertaken to determine the reinforcing effect of woven glass fibers on deflection, flexural strength, flexural modulus and impact strength of acrylic denture base polymer. METHODS: Three silanized or unsilanized woven glass fibers were used. Specimens were made by heating the denture cure resin dough containing glass fibers, which were sheathed in the dough. Specimens with four different thicknesses and of five different types were made, incorporating the glass fiber. Three-point flexural test and flywheel type impact test were employed to determine the flexural properties and impact strength. RESULTS: When specimens contained unsilanized glass fiber, the flexural strength in specimens of 1 and 2 mm thickness and the impact strength in specimens of 2 mm thickness were higher than those of specimens without glass fiber (p < 0.01). On the contrary, the flexural strength and deflection in specimens reinforced with silanized glass fiber of 1 mm thickness were significantly higher (p < 0.01, p < 0.05) than those of unreinforced specimens. Further, the impact strength in specimens reinforced with silanized glass fiber of 2 mm thickness was significantly higher (p < 0.01) than that of unreinforced specimens. Statistically significant differences were found in the flexural strength (p < 0.05) and in the impact strength (p < 0.01) when specimens of 4 mm thickness were reinforced with two or three unsilanized glass fibers. SIGNIFICANCE: The reinforcement with glass fiber was effective in thin specimens, and the reinforcing effect increased with the increase of the number of glass fibers in the case of thick specimens.     

玻璃纤维预拉伸对增韧光固化树脂基桩力学性能的影响

目的 研究玻璃纤维预拉伸对自行研制的高强玻璃纤维增韧光固化树脂复合材料（FRC）桩力学性能的影响。方法 利用加载装置将高强玻璃纤维分别拉伸0%、0.5%、1.0%后,按60%体积比浸入自行配置的光固化树脂基质,采用压膜法制成玻璃纤维增韧树脂基齿科桩,三点弯曲测试各试样的弯曲模量、弯曲强度和弯曲载荷,测试结果进行统计学分析。使用扫描电子显微镜观察FRC桩横截面和断裂面的形态。结果 玻璃纤维拉伸率对FRC桩的力学性能影响有显著差异,其中拉伸率为1.0%的玻璃纤维制成的FRC桩综合性能最佳,弯曲模量(20.40±1.40) GPa,弯曲强度(573.38±29.45) MPa,弯曲载荷(180.42±5.88) N,与未预拉伸的玻璃纤维增韧的FRC桩有显著差异(P<0.05)。结论 玻璃纤维预拉伸对FRC桩有增韧效果。